Warm blowoff?

[dinobrew]

Howdy folks-
Yesterday I was leaning against a 90Bbl FV that was actively blowing off and I noticed that the foam was pretty warm. The tank was set to 70 but the foam coming out was @ 77.
My first thought was that there was so much activity in the krausen that the foam was warming up in the head space. That got me wondering what the temp was in the top of the tank. I always thought that given proper tank geometry an active fermentation be mixing up the beer enough that the temp would be pretty consistent throughout the tank. I also checked a 60Bbl FV today and the foam was @ 75 so I dont think it is a geometry issue.

So, is the heat being generated in the krausen in the headspace, or do we have layering or mabey multiple convection cells?

I'm not to worried about it because I suspect it has been going on for a while and is part of our hose flavor. Thanks.

[ArmstrongBrew]

Resistance to Change

Todd

I think it's probably due to the resistance to change in temperature. The wort is mostly water which resists changes in temperature pretty well. Once the krausen reaches the headspace and is mostly air, it doesn't resist changes in temperature as well so it tends to rise.

I agree that I wouldn't worry about it as the yeast in the krausen are basically out of the beer and not fermenting as much as the yeast still down in the wort.

Just my $0.02.

Nick

[brewmaster 2011]

where is the thermo weld on the tank cause if it is too low then it won't give a more correct reading. Also how is the glyco run through the tank is it daisy chained cause i have notice that a daisy chain works more effectively.

[kaptn06]

thoughts

My first thought (of many) would be latent heat.

[Moonlight]

I bet is is a cell above the portion being cooled. Any chance it is a top manway tank and you can put a remote sensing thermometer into the wort? If it is a multiple jacket tank you could adjust the flows and maybe get it to behave more evenly.